A OneCart listing is a product information page which includes information of the product such as the category, listing title, description, dimension, images and sku information.
It has to firstly be set up through an ecommerce platfrom provider (Shopee, Lazada, Qoo10, Shopify, etc) which can be done in OneCart. For existing listings in other platforms, it can be imported to OneCart to be a OneCart listing.